Jack selection device for circular knitting machines

ABSTRACT

A device arranged adjacent a cam ring at jack level in a circular knitting machine. The device includes a movable cam insertable in a notch in the cam ring to maintain the continuity of the upper surface of the cam ring for action upon lower jack butts. When the cam is moved out of the notch a lever is activated to selectively act on jack butts to force the lower butts of selected jacks off the cam ring.

United States Patent Lonati [4 1 May 16, 197 2 54] JACK SELECTION DEVICEFOR [56] References Cited CIRCULAR KNITTING MACHINES UNITED STATESPATENTS [72] Inventor: Francisco Lonati, Via S. P010 1 l-Brcscia,3,184,929 5/1965 Reymes-Cole ..66/50 R Milan, Italy 3,442,097 5/1969Lonati ..66/5O R 3,093,985 6/1963 Brown ..66/42 A [221 1970 1,579,0913/l926 Denson et al. ..66/40 [21] App]. No.2 31,294

Primary Examiner-W. Carter Reynolds An0rneyGuido Modiano and AlbertJosif [30] Foreign Application Priority Data 57 ABSTRACT Apr. 30, 1969Italy 16.25lA/69 A device arranged adjacent a cam ring at jack level ina Gil-cw lar knitting machine. The device includes a movable cam in-[52] 1.1.5. Cl. ..66/50 R, 66/51, 66/57 gamble in a notch in the camring to maintain the continuity [51 Int. Cl ..D04b 15/68, D04b 15/32 ofthe upper surface of the cam ring for action upon lower jack [58] Fieldof Search ..66/25, 42, 40, 50 R, 50 A, butts. When the cam is moved outof the notch a lever is ac- 66/50 B, 57, 75, 51 tivated to selectivelyact on jack butts to force the lower butts of selected jacks off the camring.

1 Claim, 4 Drawing Figures P'ATENTEIJMAY 16 I972 3, 662 572 SHEET 1 BF 2INVENTOR.

FRHNCESCOLOMQTI AGENT PATENTEBMM 16 I972 3. 662.572

SHEET 2v 0F 2 INVENTOR. FRHNCESCO LONRTI AGENT JACK SELECTION DEVICE FORCIRCULAR KNITTING MACHINES BACKGROUND OF THE INVENTION The presentinvention relates to a device for the selection of the jacks in circularknitting machines, particularly for the manufacture of stockingsdirectly closed at the toe, i.e. stockings which are discharged from thecircular machines already closed at the toe without requiring successivesewing.

It is known that stockings obtained directly with the toe closed oncircular knitting machines have the disadvantage of a certain thickeningof the fabric at the toe.

The main object of the present invention is that of providing a devicewhich, once applied to circular knitting machines, permits the reduction(for example to one half) of the number of needles operating during themanufacture of the toe, so that it is made without thickening of thefabric.

More precisely the device according to the invention permits thereduction of the needles during the phase of manufacture of the stockingtoe, or also during other phases, on circular knitting machines notprovided with a sufiicient number of selection drums for controllingsaid reduction of the needles.

As is known, the so-called selection drums during their intermittentrotary movement operate horizontal levers which oscillate about verticalaxes, and which co-operate by means of blades with the jacks so thatthey push then, according to a predetermined order and number, into thegrooves of the needle cylinder during the selection phase. In the morecomplete circular machines various drums are provided so as to obtainany type of manufacture. With these machines it is also possible toreduce the number of needles by suitably arranging said drums. In lesscomplete machines, ie with repetition cams (memories) in place of thedrums, and hence less costly, it is not possible to provide for the saidreduction in the needles.

SUMMARY OF THE INVENTION An object of the invention is that of providinga device which permits the reduction in the needles even in these lattermachines.

Another object of the invention is that the said device permits thereduction in needles working in circular knitting machines of the typehaving eight feeds and two selection drums, or of the type having fourfeeds and one selection drum. In the types having eight feeds and fourdrums or four feeds and two drums, the drums themselves are sufiicientto control the reduction in needles, but obviously these types ofmachine are very complicated and costly.)

A further object of the invention is that of providing a device which isof simple construction, of reliable operation, of easy application andmodest cost.

According to the invention there is provided a device for the selectionof the jacks in circular knitting machines, to be arranged close to theneedle cylinder at the level of the lower ring surrounding the cylinderand provided with triangular cam portions for the raising of the jacksat the various feeds, said device comprising a member which slidesoutwards or inwards in the preferably substantially radial direction andterminating with an internal section which, in a first position,completes the upper edge of said ring between two adjacent triangularcam portions, and in a second position leaves a corresponding section ofthe upper edge of said ring open, a selection lever being mounted tooscillate at said sliding member so as to push at least some jacks intothe working position in the corresponding grooves of the needlecylinder, and control means for operating said sliding member and saidlever, setting this latter in the working position when said slidingmember is moved into said second position and viceversa setting saidlever in the rest position when said sliding member is moved into saidfirst position.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will better appear fromthe following detailed description of a preferred but not exclusiveembodiment of a device for the selection of the jacks according to theinvention, illustrated by way of example in the accompanying drawing inwhich:

FIG. 1 is a perspective view of a portion of a circular knitting machinewith eight feeds, partially disassembled and provided with the deviceaccording to the invention;

FIG. 2 is a perspective view of the device according to the invention,separated for clarity from the needle cylinder;

FIG. 3 is a diagrammatical perspective view of the device according tothe invention in the working position;

FIG. 4 is a perspective view similar to that of the preceding Figure inwhich the device is in the rest position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to said figs.the device for the selection of the jacks according to the inventioncomprises a unit I mounted on a plate 2 of a circular knitting machineat the needle cylinder 3, in an intermediate position between theselection drums 4 and 5. In the example shown, the dice is applied to acircular knitting machine of the type having eight feeds and two drums.As is known these drums rotate intermittently and are prearranged so asto operate a plurality of horizontal selection levers 6 which aremounted to oscillate about a vertical pivot 7. The internal ends of thelevers 6 act on blades 6a arranged close to the surface of the needlecylinder 3 so as to be able to push the jacks by acting on theircorresponding butts, into the grooves of the cylinder 3.

To the plate 2 a ring 8 is fixed which surrounds the cylinder 3 andcomprises triangular cam projections which, in the case of the eightfeed machine, are four in number. These projections are commonly calledcams. More precisely two control cams 9 and 10 and two memory earns 11and 12 are provided, arranged alternately. The cams l1 and 12 are calledmemory cams because they cause the precise repetition of the movementsmade by the other cams 9 and 10.

The upper edge of the cams 9101 1-12 is gleaned, that is radiallyinclined with the lower side located outwardly, as is the upper edge ofthe ring 8 between the earns 10 and 11, indicated by 13, and between thecams 9 and 12, indicated by 14 (FIGS. 3 and 4). Between the cams 9 and11 a flat section 15 is provided at which there is the group of blades60 of the drum 4. Analogously between the cams 10 and 12 another flatsection 16 is provided at which there are the blades 6a of the drum 5.

The flat sections 15 and 16 are required in order to permit themovement, between the grooves of the cylinder 3, of the jacks 17 (FIGS.3 and 4). These jacks comprise a lower butt which defines a sharp anglednotch 18 which adheres to the gleaned guiding edge of the ring 8, at thecams 9-10-11-12 and at the sections 13 and 14.

The selection device 1 according to the invention, comprises a slidingmember 19 disposed in the substantially radial direction at the cylinder3 and mounted inside a guide body 20 rigid with the plate 2. Theinternal end portion 21 of the member 19 is shaped similar to thegleaned edge of the sections 13 and 14 of the ring 8. In particular thesection 14 is notched at 22 over a portion corresponding to the end 21,so that this latter can be inserted into the notch 22 so as to completethe upper edge of the ring 8. In other words, when the portion 21 isinserted into the notch 22, that is the sliding member 19 is in itsfirst position, the upper edge of the ring 8 is perfectly equal to thatof a normal ring. The notch 22 defines a flat section of the edge of thering 8 which permits the pushing of the jacks 17 into the grooves of thecylinder 3 in a manner similar to that which it is possible to do at theflat sections 15 and 16. The pushing of the jacks 17 can be carried outby means of a horizontal selection lever 23 mounted to oscillate on avertical pin 24 and provided with an internal projection 25 which issuitably connected for engaging with the butt 26 of the jacks 17. Thelever 23 is moved against the needle cylinder 3 when the sliding member19 is in the back or second position. The drawing back of said slidingmember 19 can be obtained by means of a lever 27 pivoted at 28 to theplate 2 and acting on a block 29 fixed to said member 19. Said block 29is attached to the guide block 20 by means of a spring 30 (FIG. 2) whichthrusts the member 19 towards the cylinder 3. The position of maximumadvancement of the sliding 5 member 19 is determined by a screw 31attached to the block 29, and engaging, in its limit position, with theguide block 20.

By more or less screwing the screw 31 it is possible to adjust theposition of maximum advancement of the sliding member 19 in such amanner that the end 21 can be exactly aligned with the edge of the ring8.

The selection of the jacks 17 is done by excluding for example one half,by excluding one and then leaving the next, so that said half is notraised by the cams 9-10-11-12. The corresponding needles (not shown) arethus not operated. More precisely, one half of the jacks 17 are disposedwith their butts 17a at the level of the lever 23, while the other halfof the jacks have not butts in that zone. The arrangement of the jacksis an alternate one (FIGS. 3 and 4).

The levers 23 and 27 are attached to corresponding means of operation(not shown) which, in their turn, are connected to cam means.

From the foregoing description, the operation of the selection deviceaccording to the invention should be evident.

In the rest or first position, the sliding member 19 is in the positionof maximum advancement (FIG. 4) thrust there by the action of the spring30. In this situation, the circular machine operates in the usualmanner, in which on rotating the needle cylinder 3 (in the directionindicated by the arrow 30 A of FIG. 1), the jacks 17 are raised by thecams 9-10-11-12, as clearly shown in FIG. 4. As is known, in circularknitting machines with eight feeds, the four cams 9-10-11-12 of the ring8 cause the raising of the needles (by way of the jacks 17) at fourfeeds, while for the remaining four feeds, the raising of the needles iscaused by other cams or locks acting directly on the butts of theneedles and disposed alternately with the cams 9-10-1 lb-l2 (the cams orlocks acting on the butts of the needles are not shown in the drawings).

During manufacture of the toe, only four feeds remain in 4() operation,namely those relative to the cams 9-10-11-12. In the manufacture withdirect closing of the toes (obtained by keeping the stocking on thehooks, manufacturing the fabric of the toe and then reversing it) thenumber of needles worked is halved, in order to obtain a reduction inthe thickness of the fabric in this zone.

The reduction in the number of needles takes place, as stated, by makingthe group I operate. More precisely the lever 27 is moved in thedirection of the arrow B shown in FIG. 1 and simultaneously the lever 23is moved against the needle cylinder 3. In this way the sliding member19 is drawn backwards so as to release the notch 22, while theprojection 25 of the lever 23 approaches the needle cylinder 3 (FIG. 3).

On rotating this latter, the butts 17a of one half of the jacks l7engage with said projection 25, so that the jack 17 carrying said butts17a are pushed into the respective grooves of the cylinder 3. This ispossible in that the operation of the lever 23 takes place at the notch22 which determines a flat section in the edge of the ring 8. Themovement of the jacks 17 provided with butts 17a means that the jacksare no longer raised by the cams of the ring 8, but pass inside as shownin FIG. 3. Consequently the corresponding needles are not raised, andare thus excluded from working (i.e. they do not take the thread comingfrom the four feeds operating).

After manufacture of the toe of the stockings, the unit 1 is returned toits initial disposition, by releasing the lever 27 so as to make theslidable member 19 return into its position of maximum advancement, andreturning the lever 23 into its position distanced from the cylinder 3.The return of the member 19 is obtained without interference with thelower butts of the jacks while a group of jacks is in the inoperativeposition, that is with the lower butts pushed into the grooves of theneedle cylinder by the selection levers 6 of the drum 4,

which act on the lower butts between cams l1 and 9 as it is known inthese machines. The arrangement shown in FIG. 4 IS thus attained inwhich all the jacks 17 are raised by the cams of the ring 8 (i.e. allthe needles of the cylinder 3 are again put into operation). Hence insubstance the selection device 1 situated before the rise of the cam 12can make this cam operate as a memory cam or not, according tonecessity. As can be seen, the selection device according to theinvention is of simple structure and easy manufacture. Its applicationpresents not difficulty and allows an improved operation of circularknitting machines to be obtained which is similar to that of morecomplete machines.

I claim:

1. In a circular knitting machine having a needle cylinder with aplurality of grooves therearound, a plurality of needles longitudinallyslideable inside said grooves and a plurality of jacks for the actuationof said needles, said jacks having a lower butt and a lower end movableinto and out of said grooves, a device for the selection of said jacksaccording to a predetermined law having a lower ring surrounding theneedle cylinder and provided with triangular projections for the raisingof the jacks, said ring defining a guiding edge for said lower butt ofsaid jacks, wherein, according to the improvement, the guiding edgedefined by said triangular projections and by at least a portion of saidring arranged between two of said triangular projection is inclined inthe radial sense having a lower side located outwardly, the said portiondefining a notch along a part thereof, and wherein said device furthercomprises a sliding member movable substantially radially of the needlecylinder and provided with an inner end externally shaped as the saidnotch to move from a first position in which the said end engages withthe said notch to complete the said portion of said guiding edge into asecond position in which the said end leaves the said notch open, andwherein said device further comprises a selection lever mountedoscillatingly near said lower ring and having a projection for pushingat least one of said ends of said jacks into the said grooves of saidneedle cylinder, control means being provided to operate said selectionlever and said sliding member and activate said selection lever whensaid sliding member is in said second position.

1. In a circular knitting machine having a needle cylinder with aplurality of grooves therearound, a plurality of needles longitudinallyslideable inside said grooves and a plurality of jacks for the actuationof said needles, said jacks having a lower butt and a lower end movableinto and out of said grooves, a device for the selection of said jacksaccording to a predetermined law having a lower ring surrounding theneedle cylinder and provided with triangular projections for the raisingof the jacks, said ring defining a guiding edge for said lower butt ofsaid jacks, wherein, according to the improvement, the guiding edgedefined by said triangular projections and by at least a portion of saidring arranged between two of said triangular projection is inclined inthe radial sense having a lower side located outwardly, the said portiondefining a notch along a part thereof, and wherein said device furthercomprises a sliding member movable substantially radially of the needlecylinder and provided with an inner end externally shaped as the saidnotch to move from a first position in which the said end engages withthe said notch to complete the said portion of said guiding edge into asecond position in which the said end leaves the said notch open, andwherein said device further comprises a selection lever mountedoscillatingly near said lower ring and having a projection for pushingat least one of said ends of said jacks into the said grooves of saidneedle cylinder, control means being provided to operate said selectionlever and said sliding member and activate said selection lever whensaid sliding member is in said second position.